Just wanted to share my reassuring experiences with unlocking, confirming that no matter what you've done with your phone previously (and bricked it or not), you can have a fully functional iPhone.

Here's what I've done:

1) I purchased IPSF licence, but did not use it in the beginning.
2) I unlocked my 1.0.2 iPhone with iUnlock, successfully.
3) Upon hearing about the baseband / bricking problems originating from iUnlock with updates to 1.1.1, I followed Erica Sadun's instructions to reflash = "virginize" my iPhone's baseband. My iPhone got re-locked, of course, with the known IMEI error.
4) I used my IPSF licence and SimFree app to re-unlock my 1.0.2 iPhone.
5) The re-unlock with IPSF was successful, and I was also hopeful it had corrected any treaded corruptions in the baseband.

It did fully "repair" my iPhone (baseband, seczone).
Testimonial to the above:

6) I upgraded my IPSF unlocked iPhone to 1.1.1, which also of course upgraded the modem firmware.
7) I downgraded my iPhone to 1.0.2 as instructed on this forum, using the KMAC method.
8) I activated with iNdepencence again, using my Finnish SIM in the iPhone.
9) My iPhone remained totally SIM-unlocked and works perfectly (Calls, SMS, YouTube, Edge). The IPSF unlock survived the 1.1.1 upgrade and consequent downgrade to 1.0.2., without having to re-unlock with the 1.6 version now available.

I didn't have any problems in any part of this process: initially unlocking with iUnlock > "virginizing" baseband > re-unlocking with IPSF in 1.0.2 > upgrading to 1.1.1 > downgrading to 1.0.2. with SIM unlock intact.

So, I now have an unlocked phone that's running 1.0.2 firwmare and 04.01.13_G modem firmware. I didn't face a "brick" at any point, and can say the IPSF solution is very resistant to upgrades, downgrades and surprisingly problem free.

Also, my friend got his iPhone with firmware 1.1.1 (factory status) from NY yesterday. He downgraded it to 1.0.2, used IPSF version 1.6, and unlocked his iPhone with no problems.

I don't wish to advocate IPSF any more than I have, but I hope this post is reassurance to people who are afraid of 1.1.1 and what problems it might bring. You cannot damage or brick you iPhone beyond salvation, and you can SIM unlock it no matter what is your situation. So go buy those 1.1.1 iPhones

I am eagerly waiting for Dev Teams developments with 1.1.1.

I want to upgrade again to 1.1.1 firmware, once enough 3rd party applications have been ported and jailbreaking / activation is made easy by the Dev Team. I am also hoping their free unlock will be as resistant and problem-free as the IPSF solution, for those who don't want to pay for an unlock.

- One very happy iPhone owner!
(having boldly experimented with my iPhone)